package com.zhixi.filter;


import com.alibaba.fastjson.JSON;
import com.zhixi.common.R;
import com.zhixi.common.SharedVariablesCurrent;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * @ClassName LoginCheckFilter
 * @Author zhangzhixi
 * @Description 登录检查过滤器
 * @Date 2022-7-8 22:21
 * @Version 1.0
 */
@WebFilter(filterName = "loginCheckFilter",urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {

    //路径匹配
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {

        //强转
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        //1.获取本次请求的URI
        String requestURI = request.getRequestURI();
        log.info("拦截到的请求：{}",requestURI);

        //定义不需要处理的请求
        String[] urls = new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**",
                "/static/**",
                "/common/**",
                "/user/sendMsg",
                "/user/login"
        };

        //2.判断本次请求是否需要处理
        boolean check = check(urls, requestURI);

        //3.如果不需要处理，则直接放行
        if (check) {
            log.info("本次请求：{}，不需要处理",requestURI);
            filterChain.doFilter(request,response);
            return;
        }

        //4-1.判断登录状态，如果已登录，则直接放行
        if (request.getSession().getAttribute("employee") != null) {
            log.info("用户已登录，用户id为：{}",request.getSession().getAttribute("employee"));

            /*将用户数据放入ThreadLocal中（为了MP的公共字段自动填充）*/
            Long empId = (Long) request.getSession().getAttribute("employee");
            SharedVariablesCurrent.setCurrent(empId);

            filterChain.doFilter(request,response);
            return;
        }

        //4-2.针对移动端用户，判断登录状态，如果已登录，则直接放行
        if (request.getSession().getAttribute("user") != null) {
            log.info("用户已登录，用户id为：{}",request.getSession().getAttribute("user"));

            /*将用户数据放入ThreadLocal中（为了MP的公共字段自动填充）*/
            Long empId = (Long) request.getSession().getAttribute("user");
            SharedVariablesCurrent.setCurrent(empId);

            filterChain.doFilter(request,response);
            return;
        }

        //5.如果未登录则返回未登录结果,通过输出流方式向客户端页面响应数据
        log.info("用户未登录");
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
    }

    /**
     * 判断是否需要处理
     * @param urls 请求路径
     * @param requestURI 请求路径
     * @return 是否需要处理，true：不需要处理，false：需要处理
     */
    public boolean check(String[] urls, String requestURI){
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if (match) {
                //匹配
                return true;
            }
        }
        //不匹配
        return false;
    }
}